AUGUSTA – Maine’s trees came through another mild winter just fine, but watch out for tree bugs. We’re overdue for a bad, buggy year, according to Maine Forest Service forest entomologist Charlene Donahue.

“This year, our trees are in pretty good shape,” she said by phone Wednesday afternoon in Augusta. “We had a mild winter for a couple of years and plentiful rainfall. At this juncture, it looks pretty good for trees and, having said that, it will probably be a horrific tree bug season. We’re due.”

Maine has between 20,000 to 30,000 insect species, but those that affect trees are only about a couple of hundred, with maybe a few dozen that are more noticeable than others.

“There’s lots of bugs out there, but most of them are the good guys that don’t bother us,” she said.

The usual dastardly insects, like mosquitoes, black flies, and horse, deer and moose flies, however, will be out in usual numbers. The warm extended winter, big snow dumps on holidays, and soggy spring gives no reprieve from them, Donahue said. She’s already been bitten by black flies.

But species of pests that defoliate, maim or kill trees, could be more prolific than usual.

“Our early-season defoliator populations – the gypsy moths and Eastern tent caterpillars – are very low right now, so, that’s really good news. It’s still early in the spring, but they’re just not around, and the reason, is, that we had two quite wet springs that allowed a fungal disease to kill them off.”

Cool, soggy springs let the fungal pathogen spread throughout the populations, which due to the weather, huddled in their tents or nests.

That said, this year is the first time in 12 years that the line for Maine’s decades-long gypsy moth quarantine has expanded farther north to include certain towns in Somerset, Piscataquis and Aroostook counties. In the coming months, that line is anticipated to extend even farther north.

Donahue said warm winters have allowed the hardwood pest to survive longer.

“But it’s not like it used to be when we had outbreaks and tens of thousands of acres of woods would be brown. That’s not happening now,” she said.

What is happening though, especially in western Maine, is a spreading population of saddled prominent green-striped caterpillars that, in 2005, heavily defoliated red oak on 1,600 acres, according to “Forest and Shade Tree Insect and Disease Conditions for Maine,” the service’s 59-page summary of the 2006 situation.

Last year, the creepy crawler caused moderate defoliation of red oak, maple, beech and birch in an expanding area of western Maine. The report stated that moderate-to-heavy defoliation was noticed from the air on approximately 10,360 acres.

Another bothersome but hard to predict problem is a hardwood disease called anthracnose, which grew and spread in the last two years due to unusually wet spring, summer and fall conditions, Donahue said. It causes irregular tan or brown spots or blotches on leaves, and is often followed by defoliation.

“It was pretty striking last year. I was hiking (in western Maine) and trees that should be green by the end of July were all brown,” she said.

According to the report, in most cases, anthracnose diseases don’t pose a serious threat to long-term tree health. But, in the past two years, it was more widespread and damaging than usual. People with affected trees, especially in ornamental settings, should apply protective fungicides this year or risk lowered tree vigor and poor growth.